Finite Element Analysis And Experimental Study On Thermal-mechanical Coupling Of Rubber Belt

Track is the key component of tracked vehicles.After World War II,the hanging rubber track began to appear.Compared with all-metal track,the hanging rubber track has the advantages of damping and noise reduction to protect the road surface,but its life is far less than that of metal track.The broken block is the main failure mode of the hanging rubber track.The temperature rise of hanging rubber track accelerates the fatigue and aging of rubber materials,reduces the bond strength between the rubber block and the track,rubber bushing and track pin.The combined action of high temperature and alternating load accelerates the expansion of the debonding boundary surface and then delamination failure occurs.Because the inner temperature of the hanging rubber track is difficult to measure directly,the aim of this paper is to calculate the three-dimensional dynamic heat build-up of the rubber crawler,and focuses on improving the material test conditions to make it as consistent with the loading condition of the rubber product as possible.The temperature fields of solid tire and track shoe are calculated by different calculation methods for internal heat sources.The influences of different working conditions and different structures on the steady-state temperature field of the hanging rubber track are preliminarily explored.Firstly,the compression heat build-up process of rubber column is calculated by using the hyperelastic algorithm and viscoelastic algorithm respectively to verify the accuracy of two calculation methods for internal heat sources.For the hyperelastic algorithm,a method of determining the tensile test conditions is proposed by using the time-temperature equivalent principle to consider the temperature and strain rate,so as to obtain more accurate parameters of the hyperelastic constitutive model.For viscoelastic algorithm,a set of stress under fully relaxed state is obtained by stress relaxation experiment to fit elastic part of viscoelastic algorithm.The results show that the results of the two algorithms are close,and the viscoelastic algorithm is in good agreement with the experimental results.According to the calculation cost and the accuracy of simulation results,viscoelastic algorithm and hyperelastic algorithm are selected respectively to calculate the temperature rise of solid tire and hanging rubber track.Then,a mechanical finite element model of solid tire is established,and the material test conditions are calculated.The dissipation energy density is directly calculated as the internal heat source on the basis of viscoelasticity algorithm.The heat transfer coefficient of the outer contour of solid tire is calculated by using the convective heat transfer theory of smooth convex rotating surface and Mikic model.The solution strategy and analysis method of steady-state temperature field of solid tire are formed based on viscoelastic heat build-up algorithm.Moreover,according to the periodic arrangement and connection relationship of tracks,the Python program is compiled to fastly construct the finite element model of the whole track.A series of equivalent replacement is made by using the periodicity and symmetry of the track.Combined with the damping setting of the track pin,the track assembly process can enter into steady-state quickly,greatly reducing the calculation cost of the track mechanical model,and it makes it possible to solve the steady-state temperature field of the track based on the hyperelastic heat build-up algorithm.Finally,based on the strategy and analysis method of the steady-state temperature field,the influences of different working conditions and structure characteristics on the track temperature field are investigated.The results show that with the increase of the load on solid tire,the slip ratio between track shoe and ground,the stress increases when the track shoe passes through the solid tire,and the temperature in different positions of the track shoe increases.The increase of the angle of the clamping groove of the track board can decrease the stress concentration of the ground glue and reduce the temperature of the track shoes.However,when the angle further increases,stress will rise.Among the four different groove angle models,the model with 95 °clamping angle has the best performance in decreasing both the stress value and the maximum temperature.